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C M Magro

Publications and source records attributed to C M Magro.

At least 37 records · Page 2Linked to original sources

Analysis of clonality of atypical cutaneous lymphoid infiltrates associated with drug therapy by PCR/DGGE.

Atypical lymphocytic infiltrates that mimic cutaneous lymphoma (ie, pseudolymphoma) are often observed in skin biopsy specimens from patients with altered immune function. The latter may reflect systemic immune dysregulatory states such as collagen vascular disease or human immunodeficiency virus infection. Among the iatrogenic causes are drug therapy with agents that abrogate lymphocyte function. These drugs encompass the anticonvulsants, antidepressants, phenothiazines, calcium channel blockers, and angiotensin-converting enzyme inhibitors. The appellation of lymphomatoid hypersensitivity reaction has been applied to cases of drug-associated pseudolymphoma. Pathologically and clinically, the distinction of such cases from cutaneous lymphoma is difficult. We employed the polymerase chain reaction (PCR) on archival material of proven drug-associated lymphomatoid hypersensitivity reactions both to explore its utility as an adjunct in diagnosis and to investigate the genotypic aberrations induced by drug therapy. Formalin-fixed, paraffin-embedded biopsy specimens from seven cutaneous T-cell lymphomas (CTCL), one nodal T-cell lymphoma, two cutaneous B-cell lymphomas, three typical hypersensitivity reactions, one tonsil, and 14 lymphomatoid hypersensitivity reactions were studied. Control cases for which DNA derived from fresh tissue was used include the Jurkat T-cell tumor line, placenta, one nodal B-cell lymphoma, and one case of reactive lymph node hyperplasia. DNA was obtained and purified by standard methods, then amplified with oligonucleotide primers specific for the T-cell receptor gamma locus and the immunoglobulin heavy chain genes. T-cell amplicons were analyzed by denaturing gradient gel electrophoresis (DGGE) and B-cell amplicons by either nondenaturing polyacrylamide or agarose gel electrophoresis. The nodal and Jurkat T-cell lymphomas, six of seven CTCL, one cutaneous B-cell lymphoma, and 2 of 14 lymphomatoid hypersensitivity reactions showed dominant ("monoclonal") T-cell gene rearrangement patterns, and the remainder of cases were polyclonal. A causal relationship between drug therapy and skin eruption was ascertained in the two patients showing T-cell rearrangements, and both experienced complete and sustained lesional resolution on discontinuation of the implicated drug. The only immunoglobulin heavy chain gene rearrangements detected by PCR were in two of the three B-cell lymphomas. We conclude that PCR/DGGE is a powerful method for assaying T-cell clonality in archival tissue and can aid in the discrimination of reactive from malignant cutaneous infiltrates with appropriate clinicopathologic correlation. Recognition that a monoclonal TCRgamma rearrangement can be observed in cases of drug-associated lymphomatoid hypersensitivity may help in avoiding a misdiagnosis of malignant lymphoma.

Adolescent↗

Recent advances in the pathology of cutaneous drug eruptions.

Cutaneous reactions to drug therapy may be of either immunologic or nonimmunologic etiology. It is important that the dermatologist and pathologist be familiar with these types of cutaneous reactions. This article discusses the clinical features, pathogenesis, and histopathology of various cutaneous drug eruptions.

Adult↗

The cutaneous pathology associated with seropositivity for antibodies to SSA (Ro): a clinicopathologic study of 23 adult patients without subacute cutaneous lupus erythematosus.

Antibodies to Ro/SSA are found in patients with subacute cutaneous lupus erythematosus (SCLE), complement deficiency lupus erythematosus, systemic lupus erythematosus (SLE), neonatal lupus erythematosus, and Sjögren syndrome (SS). Most studies describing the cutaneous pathology associated with anti-Ro antibodies have been of patients with SCLE. Over a 42-month period, we encountered skin biopsy specimens from 23 anti-Ro-positive patients who did not have SCLE: 15 had SLE variably manifesting as SCLE-like rashes; malar erythema; a dermatomyositis-like rash; vascular disease involving cutaneous, cardiac, peripheral, and central nervous systems; restrictive pulmonary disease; periorbital edema; and myositis. Two patients had primary Sjögren syndrome, one had primary antiphospholipid antibody syndrome, and two had rheumatoid arthritis; all five had clinical evidence of cutaneous vasculopathy encompassing livedo, perniosis, and palpable purpura. Three additional patients presented with folliculocentric purpura without other stigmata to permit classification as a specific connective tissue disease. In the SLE patients, biopsy specimens of photodistributed eruptions showed an interface dermatitis accompanied by superficial vascular plexus density reduction. Vasculopathic reactions in patients with and without SLE comprised neutrophilic, lymphocytic, or pauciinflammatory thrombogenic subtypes. Although at times a marker of SCLE, the identification of anti-Ro antibodies may isolate a subset of patients at higher risk of multiorgan vasculopathy, myositis, and progressive pulmonary disease. We postulate that many of the features seen in these patients reflect the sequelae of antibody mediated endothelial cell injury.

Adult↗

A clinical and histologic study of 37 cases of immunoglobulin A-associated vasculitis.

Immunoglobulin (Ig) A-associated vasculitis is commonly equated with the multiorgan systemic vasculitic syndrome Henoch-Schonlein purpura (HSP), which occurs predominantly in the pediatric age group. By natural language search of the databases of two outpatient dermatopathology practices, the authors selected for review 37 cases of IgA-associated vasculitis, 23 of which were associated with antecedent infection, most commonly of the upper respiratory tract. Criteria for a diagnosis of HSP were met in 15 cases, 13 of which were in the setting of prior infection. Lower extremity skin involvement was ubiquitous. A more widespread form of vasculitis was also seen, particularly in the setting of previous infection. Several of the patients with previous infection had underlying medical illnesses including rheumatoid arthritis, atopy, renal failure, lupus erythematosus, insulin dependent diabetes mellitus, autoimmune thyroid disease, and Wegener's granulomatosis. In those patients lacking an apparent microbial trigger, Sjogren's disease with anti-Ro antibodies and hypergammaglobulinemia, lupus erythematosus, inflammatory bowel disease, IgA paraproteinemia, bronchogenic and prostatic carcinoma, cryoglobulinemia, and lymphoma were uncovered. Regardless of whether an infectious stimulus was implicated, certain cofactors with the potential to enhance vascular injury were uncovered; these included anti-Ro antibodies, antineutrophil cytoplasmic antibody, diabetic microangiopathy, and a hyperviscosity state. In the infective group, a pustular vasculitis, defined as a neutrophilic vascular reaction in concert with epithelial pustulation, was seen in 81% of cases versus 33% in the noninfectious group (p = 0.02). The prototypic histomorphology in the noninfective group was one of a mild cell poor leukocytoclastic vasculitis; Vasculitis was of greater severity in patients with antecedent infection (p = 0.026). An infectious trigger, typically of mucosal origin, can frequently be identified in patients with cutaneous IgA-associated vasculitis, especially those with the symptom complex of HSP. The light microscopy appears to distinguish patients who have an infectious trigger from those who do not. IgA-associated vasculitis may be a clue to the presence of certain underlying disorders where there is immune dysregulation or enhanced susceptibility to immune complex entrapment.

Adolescent↗

Pseudoporphyria associated with Relafen therapy.

Various oral medications including nonsteroidal anti-inflammatory drugs (NSAIDs) have been associated with pseudoporphyria, although the pathogenetic basis has not been elucidated. A novel NSAID nabumetone (Relafen) has become popular because of its minimal gastrointestinal side effects. Its association with pseudoporphyria is not reported save for its listing in the Physician's Desk Reference (PDR) as a possible side effect. Biopsies of lesional skin from 4 patients manifesting blisters and erosions on the hands and face within 4 months of starting nabumetone were submitted for light microscopic and immunofluorescent (IF) studies. Histories and serology were obtained. Two patients had rheumatoid arthritis (RA), 1 had mixed connective tissue disease (MCTD), and 1 received diltiazem. All 4 had antinuclear antibodies. Characteristic clinical, light microscopic and IF features in the absence of elevated urine porphyrin levels confirmed a diagnosis of pseudoporphyria in all 4 patients. Biopsies in three patients showed features attributed to underlying connective tissue disease (CTD), including ectasia of the superficial vascular plexus, mild leukocytoclastic vasculitis, superficial and deep perivascular lymphocytic infiltrates with dermal mucinosis, granular deposition of IgM along the dermoepidermal junction indicative of a positive lupus band test, and of IgG and C5b-9 within keratinocytes. Nabumetone (Relafen) can provoke pseudoporphyria; an underlying CTD diathesis may be a predisposing factor.

Adult↗

Lichenoid and subacute cutaneous lupus erythematosus-like dermatitis associated with antihistamine therapy.

The authors report the occurrence of lichenoid and/or subacute lupus erythematosus-like eruptions in a group of patients receiving agents with antihistaminic properties. In 1 of the patients the eruption clinically resembled lichen planus, while in 5 patients the eruption resembled subacute cutaneous lupus erythematosus (SCLE). At a light microscopic level all cases showed a lichenoid dermatitis and in 4 cases the lesions were interpreted as representing subacute lupus-like eruptions by virtue of the presence of alternating cell poor and lichenoid interface dermatitis, suprabasilar lymphocytosis around degenerating keratinocytes, and dermal mucinosis. Despite the resemblance at a clinical and light microscopic level to SCLE, anti-Ro seropositivity could not be established in any of the cases. One case, however, did demonstrate antihistone antibodies in concert with a high antinuclear antibody titer. A causal association was implicated by virtue of lesional resolution following drug withdrawal. The association of cutaneous eruptions resembling SCLE with antihistamine intake is seemingly a novel one. The possible pathogenetic basis of the eruptions is discussed.

Aged↗

Diagnostic clues to dermatitis artefacta.

We report a case of dermatitis artefacta in a 36-year-old man who had progressive, nonhealing ulcers and swelling of his right arm. The lesions spared two tattoos. In addition, our patient had several of the classic features of dermatitis artefacta. We outline more than a dozen diagnostic clues that may help the clinician faced with this difficult problem.

Adult↗

The interstitial granulomatous drug reaction: a distinctive clinical and pathological entity.

We present 20 patients in whom drug therapy was associated with interstitial histiocytic infiltrates with variable degeneration of collagen and elastic fibers mimicking early lesions of granuloma annulare (GA). Most patients had a reproducible clinical presentation comprising erythematous-to-violaceous, nonpruritic plaques, often with an annular pattern, predominantly involving inner aspects of the arms, medial thighs and intertriginous areas. The most frequent clinical differential diagnoses included cutaneous T cell lymphoma, erythema annulare centrifigum (EAC), GA, and lupus erythematosus. A drug reaction was suspected in only 3 cases. The implicated drug classes included calcium channel blockers, angiotensin converting enzyme inhibitors, beta-blockers, lipid-lowering agents, antihistamines, anticonvulsants and antidepressants. Patients were often on two or more of these drugs; all have been associated with pseudolymphomatous infiltrates of the skin, the presumptive basis of which is iatrogenic pertubation of immune function. The defining histomorphology was diffuse infiltration of the interstitium by lymphocytes and histiocytes with piecemeal fragmentation of collagen and elastic fibers in concert with a vacuolar interface dermatitis. Ten cases showed intermediate and transformed lymphocytes with hyperchromatic convoluted nuclei disposed interstitially within the dermis or along the dermoepiderma junction with variable epidermotropism. In the 15 patients who discontinued the implicated drug, lesional resolution occurred. We propose the designations interstitial granulomatous drug reaction for this novel cutaneous reaction pattern.

Aged↗

Sterile neutrophilic folliculitis with perifollicular vasculopathy: a distinctive cutaneous reaction pattern reflecting systemic disease.

The authors prospectively encountered skin biopsies from 20 patients which demonstrated a neutrophilic or suppurative and granulomatous folliculitis accompanied by a folliculocentric neutrophilic vascular reaction of Sweet's-like or leukocytoclastic vasculitis subtypes. While in each case the histomorphology raised diagnostic consideration of bacterial folliculitis, patients frequently expressed systemic complaints such as arthritis, fever, and malaise, and special stains for micro-organisms were negative. Among the clinical presentations were folliculitis, vasculitis, acneiform eruptions, vesiculopustular lesions, and erythema nodosum-like lesions, with the legs, arms, and upper back being the most commonly involved sites. Nineteen patients were found to have specific underlying systemic diseases, namely, inflammatory bowel disease, Reiter's disease, Behçet's disease, hepatitis B, connective tissue disease including mixed connective tissue disease and rheumatoid arthritis, scrofuloderma, and hematologic dyscrasias. The other patient had antecedent bacterial sinusitis in the setting of atopy. The folliculocentric nature of these lesions may reflect preferential processing of antigens through the hair follicle and/or homology between bacterial and follicular heat shock proteins in the susceptible host, namely, one who responds excessively to exogenous antigenic triggers. Folliculitis with folliculocentric vasculopathy may be a clue to underlying systemic disease and/or an extracutaneous infection. Certain light microscopic features in concert with the clinical presentation may distinguish such cases from conventional infectious folliculitis.

Adolescent↗

A distinctive cutaneous reaction pattern indicative of infection by reactive arthropathy-associated microbial pathogens: the superantigen ID reaction.

The two major cutaneous expressions of infective states are infections of the skin by viable organisms and immunological responses to nonviable microbial antigens or, in the case of molecular mimickry, their human analogues. These immunological responses are designated as cutaneous id reactions, and manifest a histomorphology similar to that seen at the primary infective site. This study presents the clinical and histological findings in 16 patients who developed skin eruptions associated with extracutaneous or systemic infections. There was a striking female predominance; patients ranged in age from 10 to 78 years. The majority of cases manifested skin lesions which clinically resembled Sweet's syndrome, erythema multiforme and/or erythema nodosum. Fever, arthralgia, oligoarthritis, mucosal ulcers of the mouth and/ or genital tract and uveitis were additional features in some cases. Isolated clinical presentations included a petechial rash in a stocking and glove distribution, papular dermatitis, a morbilliform eruption and annular erythema. Among the medical and family histories were atopy and stigmata associated with connective tissue disease (CTD). Two patients were ingesting drugs with known immune dysregulating properties. Skin biopsies showed focal lymphocytic interface dermatitis, a diffuse interstitial histiocytic infiltrate, and a mononuclear cell predominant vascular reaction which in some cases represented vasculitis by virtue of manifesting concomitant luminal or mural fibrin deposition. Eosinophils, eczematous alterations, and papillary dermal edema were identified in a minority of cases. All patients had evidence of a prior or concurrent infection, based on either positive IgM serology for specific microbes or cultures. Among the implicated pathogens were cytomegalovirus, parvovirus B19, streptococcus, mycoplasma, klebsiella, and Borrelia burgdorferi. All of these organisms are among those associated with reactive arthritis, a phenomenon that was seen in some cases. The histology suggested florid cell mediated immunity (CMI), which the authors attributed to the superantigen properties held by the aforesaid pathogens. Skin lesions and constitutional symptoms resolved quickly with antimicrobial therapy in 7 of 9 cases causally linked to bacteria. Spontaneous resolution occurred in 5 of 6 virally mediated eruptions. The other 4 patients were given topical steroids or prednisone; these included 1 patient with Borrelia burgdorferi infection and 1 patient with radiographic evidence of pneumonia who was never cultured, 1 patient with parvovirus B19 infection, and 1 patient with pneumococcal pneumonia and concomitant sarcoidosis. It is the authors' belief that the eruptions seen in these patients may in part reflect a genetic or iatrogenic predisposition to respond excessively to certain infectious triggers.

Adolescent↗

Idiopathic perniosis and its mimics: a clinical and histological study of 38 cases.

Perniosis is a term applied to cold-induced painful or pruritic erythematous or violaceous acral papular or nodular lesions. We examined 39 skin biopsies from 38 patients who presented with acral purpuric lesions, suggesting a diagnosis of perniosis clinically or pathologically. The presence of a systemic or extracutaneous disease was established in 17 patients, including 5 with systemic lupus erythematosus (SLE), 3 with antiphospholipid antibodies, in 1 in whom there was underlying HIV disease, 2 with viral hepatitis, 2 with rheumatoid arthritis (RA), 2 with cryofibrinogenemia, 1 with hypergammaglobulinemia, 1 with iritis, and 1 with Crohn's disease. In the other 21 patients, the clinical presentations prompted further studies in 12, which showed a positive antinuclear antibody (ANA) in 10. A diagnosis of idiopathic perniosis (IP) was rendered in all 21 of these patients including those in whom a positive ANA was discovered, based on the absence of any other serological markers, signs, or symptoms indicative of a specific systemic disease complex; many had Raynaud's phenomenon, small joint arthralgias, atopy, or a family history of either connective tissue disease or Raynaud's disease. The histopathology of IP comprised a superficial and deep angiocentric lymphocytic infiltrate with papillary dermal edema and lymphocytic exocytosis directed to retia and acrosyringia. A few cases showed a mild vacuolopathic or lichenoid interface dermatitis, adventitial dermal mucinosis, lymphocytic eccrine hidradenitis, vascular ectasia, and thrombosis confined to dermal papillae capillaries. The biopsies from patients with iritis, RA, and Crohn's disease showed a granulomatous vasculitis and a granuloma annulare-like tissue reaction. The biopsies from the patients with SLE, cryofibrinogenemia, primary antiphospholipid antibody syndrome, and hypergammaglobulinemia shared a similar histopathology comprising an interface dermatitis, superficial and deep angiocentric and eccrinotropic lymphocytic infiltrates, vascular ectasia, and dermal mucinosis with prominent involvement of the eccrine coil. Many cases did not show features of IP, namely papillary dermal edema, thrombosis of dermal papillary capillaries, and lymphocytic exocytosis into the retia and acrosyringia. There was frequent vascular fibrin deposition involving reticular dermal vessels. The latter two variables were statistically significant discriminators between IP and in perniotic lesions observed in the setting of underlying systemic disease. With respect to the latter, some cases occurred in the setting of cold exposure and were designated by us as "secondary perniosis" (SP), whereas others showed no specific association with cold exposure and were designated as perniotic mimics (PMs) based exclusively on the gross and microscopic morphology of the lesions.

Adolescent↗

Subacute cutaneous lupus erythematosus arising in the setting of calcium channel blocker therapy.

After 6 months to 5 years of calcium channel blocker (CCB) therapy for arterial hypertension, nine patients developed photoinduced annular or papulosquamous eruptions consonant clinically with subacute cutaneous lupus erythematosus (SCLE). Four patients were receiving diltiazem, four received verapamil, and one was taking nifedipine. Serology showed antinuclear antibodies (ANA) in seven of nine patients, anti-Ro antibodies in five, and anti-La antibodies in five, with three patients having only anti-La antibodies. Skin biopsy specimens in all nine patients were held to be characteristic of SCLE based on light microscopy, direct, and indirect immunofluorescence. The CCB was discontinued in all; in 8 patients in whom the CCB was stopped, the eruption resolved. A proposed mechanism by which the CCBs may have precipitated the eruptions is offered.

Aged↗

A novel nonepidermolytic palmoplantar keratoderma: a clinical and histopathologic study of six cases.

BACKGROUND: Some hereditary palmoplantar keratodermas (PPK) have been defined at the molecular level. OBJECTIVE: Our purpose was to establish the cause of a hereditary PPK with unique histopathologic findings in the epidermis. METHODS: Investigative studies included light and electron microscopy and determination of genomic DNA sequence. RESULTS: Six patients with PPK were found to have unique changes in the epidermis characterized by orthokeratosis, parakeratosis, perinuclear vacuolization, and keratohyalin granules that varied in size and shape and were located in the cell periphery. Electron microscopy showed the perinuclear region contained many ribosomes and vacuoles and was surrounded by a tonofibril shell. Family involvement suggested a dominant disorder. However, no mutation of keratin genes 1, 6a, 9, or 16 was found. CONCLUSION: The histopathologic features of this unique PPK most closely resemble Curth-Macklin ichthyosis for which the genetic basis has not been established. Further genetic studies are needed.

Biopsy↗

A distinctive vesiculopustular eruption associated with hepatobiliary disease.

BACKGROUND: Cutaneous manifestations of hepatobiliary disease may be a clue to the clinical diagnosis. We encountered a form of vesiculopustular eruption in five patients with hepatobiliary disease. A similar eruption has been described in the setting of ulcerative colitis, and has received the designation of vesiculopustular pyoderma gangrenosum. METHODS: Skin biopsy specimens were examined by conventional histopathologic methods and, in three cases, fresh tissue was available for direct immunofluorescence examination. A diagnosis of hepatobiliary disease was known in three of the patients and in the other two it was established by the skin biopsies. RESULTS: All skin biopsies of the five patients showed a neutrophilic dermatosis that had two morphologies. One was characterised by superficial neutrophilic dermolysis with subepidermal bulla formation and the other by a nonulcerating destructive suppurative folliculitis and perifollicular neutrophilic dermolysis. Both were frequently accompanied by a neutrophilic and lymphotic eccrine hidradermitis and a Sweet's syndrome-like vascular reaction. The lesions were held to represent a novel vesiculopustular eruption with features reminiscent of pyoderma gangrenosum. CONCLUSIONS: We propose the term vesiculopustular eruption of hepatobiliary disease for this distinctive clinicopathologic entity, which bears a strong histologic resemblance to pyoderma gangrenosum. Patients with a known hepatopathy who present with necrotizing vesicles and pustules may have such an eruption. The onset may be the first clue to or herald an exacerbation of underlying liver disease.

Adult↗

Mixed connective tissue disease. A clinical, histologic, and immunofluorescence study of eight cases.

A study of the cutaneous eruptions of eight patients with mixed connective tissue disease (MCTD) was performed to better characterize its dermatopathology and to explore a role for the membrane attack complex of complement C5b-9 in lesional pathogenesis. Nine lesional skin biopsies were obtained from eight patients with MCTD and analyzed by conventional light microscopy. Direct immunofluorescence (IF) and indirect IF using a monoclonal antibody to C5b-9 were applied in six and five cases respectively. The biopsied cutaneous eruptions were characterized clinically as photo-distributed erythematosus annular and/or papulosquamous lesions mimnicking subacute cutaneous lupus erythematosus (SCLE) in five of eight patients as an ill-defined, telangiectatic, scaly patch on the face in one patient, palpable purpura in one patient, and dorsal hand blisters resembling porphyria cutanea tarda (PCT) in another. With the exception of the latter two patients, the histology appeared similar, comprising a cell poor and/or lichenoid interface dermatitis with suprabasilar exocytosis around necrotic keratinocytes in the absence of deep periadnexal or perivascular extension or conspicuous follicular plugging, a pattern similar to that of SCLE. However, the lesions differed from SCLE by virtue of vasculopathic alterations comprising vascular ectasia, hypovascularity, and/or luminal thrombosis confined to the superficial vascular plexus and a sclerodermoid tissue reaction, the latter seen in two cases. One biopsy showed a pustular leukocytoclastic vasculitis (LCV). In another case, a biopsied hand blister demonstrated a PCT-like appearance histologically, namely, pauci-inflammatory subepithelial blister formation with hyalinization of dermal papillae capillaries accompanied by an LCV. There was nuclear keratinocyte decoration with IgG and C5b-9 in all cases studied, accompanied by a positive lupus band test in two cases and homogenous deposition of immunoreactants along the dermoepidermal junction and within vessels in the PCT-like eruption. Granular vascular decoration with immunoreactants including C5b-9 was seen in two LCV cases and in two biopsies from rashes clinically mimicking SCLE. Although the epidermal pathology of MCTD mimicks that of SCLE, a concomitant vasculopathy paralleling that seen in skin lesions of dermatomyositis distinquishes the dermatopathology of MCTD from that of SCLE. Corroborating the role of microangiopathy in the pathogenesis of the skin lesions of MCTD was the demonstration of C5b-9 in blood vessels. The deposition of C5b-9 in keratinocytes may explain the pattern Of IgG decoration of keratinocytes; the formation of plasmalemmal pores may permit binding of immunoglobulin to antigens in the nucleus and/or cytosol. The C 5b-9 complex may be the effector mechanism of epithelial and/or endothelial cell injury in MCTD or may serve to augment the effects of antibody-dependent cellular cytotoxicity.

Adult↗

Atypical lymphoid infiltrates arising in cutaneous lesions of connective tissue disease.

Atypical lymphoid infiltrates occurring in the setting of connective-tissue disease (CTD) comprise malignant neoplasms of B-cell or T-cell phenotypes and various reactive lymphoid hyperplasias, such as myoepithelial sialadenitis, lymphocytic thyroiditis, and lymphocytic interstitial pneumonitis. We describe 17 patients with atypical lymphoid infiltrates arising in cutaneous lesions of CTD, the spectrum of which included lupus erythematosus, dermatomyositis, relapsing polychondritis, and lichen sclerosus et atrophicus. There were two principal categories, pseudolymphoma and malignant lymphoma, the former representing 15 of the 17 cases. The clinical and histologic features and possible pathogenetic mechanisms are discussed.

Adult↗

The clinical and histomorphological features of pityriasis rubra pilaris. A comparative analysis with psoriasis.

Pityriasis rubra pilaris (PRP) is an idiopathic erythematous scaling eruption which can be difficult to distinguish from psoriasis. We explored the clinical features, including background medical illnesses and potential triggers in patients with PRP, and also its histomorphologic spectrum. Patients with PRP were selected by natural language search of dermatopathology databases containing 250,000 cases accessioned over a 3-year period. A detailed medical history was obtained on each patient via office chart review and patient interviews. We compared the histologic findings in skin biopsies from patients with PRP to those of biopsies matched for site and age from control patients with psoriasis. Certain aspects of the clinical presentations encountered in the study group patients have not been previously emphasized, including eruptions compatible with a vesiculobullous disorder in 4 patients. Several patients had evidence of underlying iatrogenic or systemic immune dysregulatory states and certain triggers could be isolated such as emotional stress and prior exposure to microbial pathogens. Histomorphologic features predictive of PRP included follicular plugging, an increased granular cell layer, and acantholysis. While seen in a minority of biopsies of PRP, morphologic discriminators supportive of a diagnosis of psoriasis included neutrophils in the parakeratotic scale crust, and dermal papillae capillary ectasia with vessels lying in direct apposition to the epidermis. Other morphologic features were encountered in biopsies of PRP which have received little emphasis in the dermatopathology literature, including epithelial atrophy, significant dermal inflammation, the presence of eosinophils and plasma cells within the inflammatory infiltrates, an abnormal granular cell layer, and epidermolytic hyperkeratosis, albeit none were statistically signficant predictors of PRP over psoriasis. Nevertheless, their identification emphasizes the varied histologic spectrum of PRP. The almost ubiquitous finding of acantholysis and the presence of an abnormal granular cell layer in many biopsies of PRP suggests that abnormal keratins or defects in the retinol signalling pathway may be of pathogenetic importance.

Aged↗

The immunofluorescent profile of dermatomyositis: a comparative study with lupus erythematosus.

We have demonstrated a role for microvascular injury mediated by the membrane attack complex of complement (C5b-9) in the genesis of cutaneous lesions of dermatomyositis (DM) (1). The purpose of this study is to revisit the immunofluorescent (IF) profile of DM, to further investigate the role of C5b-9 in the pathogenesis of cutaneous lesions, and to see if any features of the IF profile reliably distinguish DM from LE. Lesional skin biopsies from 24 patients with clinical findings characteristic of DM were received in formalin and in Michel's transport medium. Conventional light microscopy, and IF studies with antibodies monospecific for IgG, IgA, IgM, C3, fibrin and C5b-9 were performed. The control group comprised biopsies from 31 patients with well-documented LE. A positive lupus band test (LBT) correlated highly with a diagnosis of LE, with a sensitivity of 64.5% and a specificity of 95.6% (p=0.001). The LBT was most sensitive in the setting of DLE and SLE and was least sensitive in the setting of SCLE. The finding of vascular C5b-9 deposition correlated with a diagnosis of DM versus LE (p=0.001) although the false positive rate was 21.4%. The false negative rate was reduced when vascular C5b-9 was seen in the absence of antibodies to Ro, La, or RNP. While a negative LBT correlated with a diagnosis of DM (p=0.001), the specificity was only 64.5%. However, when it was seen in concert with C5b-9 along the DEJ, specificity was increased to 80.6% (p=0.001). The presence of C5b-9 in vessels and along the DEJ in concert with a negative LBT was predictive of DM (p=0.001) with a specificity of 93.5%, sensitivity of 78.3%, a false positive rate of 10% and a false negative rate of 14.7%. The combination of a negative LBT, vascular C5b-9 deposition and negative serology for Ro, La, and RNP was a predictor of DM versus LE with a sensitivity of 90.5%, a specificity of 96.8%, a false positive rate of 5% and a false negative rate of 6.2% (p=0.001). The IF profile of DM in lesional skin comprises a negative LBT, deposition of C5b-9 within vessels and along the DEJ, and variable keratinocyte decoration for IgG and C5b-9. The most statistically powerful predictor of DM is the combination of a negative LBT with vascular C5b-9 deposition and negative serology for antibodies to Ro, La, Sm, and RNP. Demonstration of a negative LBT in all but 1 case of DM suggests that the DEJ is not a primary site for antigen-antibody interaction. We postulate that the aforementioned IF findings reflect humorally mediated injury of endothelium and keratinocytes, effected by C5b-9.

Adult↗